I believe that the notion of all sin being "equally" wrong is both unscriptural and, frankly, ridiculous. The OT law takes pains to point out the punishments for various sins. That, incidentally, is the PROPER understanding of "eye for an eye" and "tooth for a tooth" - not the twisted intepretation that says "eye for an eye/tooth for a tooth" is biblical support for vigilante or personal revenge justice.
Back to your point, the following passages show that God, in His divine legal economy, demonstrates perfect justice and equity by demanding payments and punishments in proportion to the injuries and offences:
Exodus 21:24
Exodus 21:27
Leviticus 24:20
Deuteronomy 19:21
I believe then, one can apply "proportionality of offences" to the proportionality of sins in general.
Insofar as the origin of "all sin is equal and will be punished equally" - to my knowledge, that's not taught expressely that way. I suppose, proponents of this belief might say the following:
"if one was to commit only one sin in one's entire life, and that was just stealing a $1 chocolate bar, and that person died having never been saved, their judgment would be eternal damnation--the same punishment that a "typical" sinful person, since Holy God cannot tolerate sin--therefore, the punishment for all sins is the same."
I would argue that if while the logic of that hypothetical scenario is technically true, it confuses the principles of general, eternal punishment for unforgiven sin in the case of the unsaved, and the treatment of sins and offences in the eyes of earthly authorities--parents, church leadership, civic magistrates, etc.
Indeed, if that principle was to be logically applied, punishing all sins equally would mean all sins would have to be punished with the "full sentence" (death) required for capital sins such as murder, etc. So, forget the rod for a foolish son - grab some rocks ... You can see where that wil take you ...
Just my
dl
[Edited on 4-10-2006 by Cuirassier]